<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    function sum([] = null) {
      let sum1 = 0
      for (let i = 0; i < arr.length; i++) {
        sum1 += arr[i]
      }
      console.log(sum1)
    }
    let arr = [23, 53, 55, 76, 66, 87, 99, 100]
    sum(arr)
  </script>
</body>

</html>